Total synthesis of (4S,10R)-4-hydroxy-10-methyl-11-oxododec-2-en-1,4-olide and related bioactive marine butenolides
摘要:
Marine-derived microorganisms produce structurally diverse butenolides possessing a variety of bioactivities. Described here is the total synthesis of (4S, 10R)-4-hydroxy-10-nnethyl-11-oxododec-2-en-1,4-olide and a related butenolide containing anti stereochemistry at C10-C11. A three-module coupling strategy has been established for synthesis of the stereoisomers of the naturally Occurring butenolides by assembling the C3-C7 and C9-C12 fragments via double alkylation of a 1,3-dithiane. The C10-C11 stereochemistry could be easily controlled by an asymmetric aldol condensation, while the butenolide unit was efficiently constructed according to the ring-closing metathesis protocol. (C) 2008 Elsevier Ltd. All rights reserved.
The application of a mechanistic model leads to the extension of the Sharpless asymmetric dihydroxylation to allylic 4-methoxybenzoates and conformationally related amine and homoallylic alcohol derivatives.
摘要:
The scope and utility of the Sharpless asymmetric dihydroxylation has been expanded to include the use of allylic 4-methoxybenzoates as precursors of a wide variety of substituted chiral glycerol derivatives. The allylic 4-methoxybenzoyl group was found to be superior to other allylic alcohol protecting groups with respect to both yield and enantiomeric purity of the product. For example, asymmetric dihydroxylation of allyl 4-methoxybenzoate (6a) using the (DHQD)(2)PYDZ . OsO4 (1 . OsO4) catalyst system affords (S)-3-(4-methoxybenzoyloxy)-1,2-propanediol (7a) in >99% yield and 98% ee. The 4-methoxybenzoates of a variety of other allylic alcohols also serve as excellent substrates, in contrast to the parent alcohols themselves. The efficient asymmetric dihydroxylation of homoallylic 4-methoxyphenyl ethers (12a and 15), allyl 9-fluorenimine (18b), bis(homoallyl) 4-methoxybenzoate (14) and other structurally related substrates is also described. This methodology was developed under mechanistic guidance from the transition state model advanced earlier by us for the bis-cinchona alkaloid catalyzed asymmetric dihydroxylation reaction. The 4-methoxybenzoyl group functions not only to selectively protect one of the hydroxy groups of the product triol for subsequent synthetic manipulation but also to provide an extended binding group that participates in hydrophobic and aryl-aryl interactions with the U-shaped binding pocket of the (DHQD)(2)PYDZ . OsO4 catalyst (1 . OsO4), thereby enhancing enantioselectivity.
Improved enantioselective dihydroxylation of bishomoallylic alcohol derivatives using a mechanistically inspired bis-cinchona alkaloid catalyst
作者:E.J. Corey、Mark C. Noe、Alice Y. Ting
DOI:10.1016/0040-4039(96)00163-3
日期:1996.3
The catalytic dihydroxylation of p-methoxybenzoate esters of various bishomoallylicalcohols proceeds with excellent enantioselectivity and, in the case of diolefins, with imporved regioselectivity using a designed catalyst that incorporates an N-anthracenylmethyl group to enhance catalyst-substrate binding interactions.
The application of a mechanistic model leads to the extension of the Sharpless asymmetric dihydroxylation to allylic 4-methoxybenzoates and conformationally related amine and homoallylic alcohol derivatives.
作者:E. J. Corey、Angel Guzman-Perez、Mark C. Noe
DOI:10.1021/ja00149a003
日期:1995.11
The scope and utility of the Sharpless asymmetric dihydroxylation has been expanded to include the use of allylic 4-methoxybenzoates as precursors of a wide variety of substituted chiral glycerol derivatives. The allylic 4-methoxybenzoyl group was found to be superior to other allylic alcohol protecting groups with respect to both yield and enantiomeric purity of the product. For example, asymmetric dihydroxylation of allyl 4-methoxybenzoate (6a) using the (DHQD)(2)PYDZ . OsO4 (1 . OsO4) catalyst system affords (S)-3-(4-methoxybenzoyloxy)-1,2-propanediol (7a) in >99% yield and 98% ee. The 4-methoxybenzoates of a variety of other allylic alcohols also serve as excellent substrates, in contrast to the parent alcohols themselves. The efficient asymmetric dihydroxylation of homoallylic 4-methoxyphenyl ethers (12a and 15), allyl 9-fluorenimine (18b), bis(homoallyl) 4-methoxybenzoate (14) and other structurally related substrates is also described. This methodology was developed under mechanistic guidance from the transition state model advanced earlier by us for the bis-cinchona alkaloid catalyzed asymmetric dihydroxylation reaction. The 4-methoxybenzoyl group functions not only to selectively protect one of the hydroxy groups of the product triol for subsequent synthetic manipulation but also to provide an extended binding group that participates in hydrophobic and aryl-aryl interactions with the U-shaped binding pocket of the (DHQD)(2)PYDZ . OsO4 catalyst (1 . OsO4), thereby enhancing enantioselectivity.
Total synthesis of (4S,10R)-4-hydroxy-10-methyl-11-oxododec-2-en-1,4-olide and related bioactive marine butenolides
作者:Wei-Min Dai、Lei Shi、Yannian Li
DOI:10.1016/j.tetasy.2008.06.028
日期:2008.7
Marine-derived microorganisms produce structurally diverse butenolides possessing a variety of bioactivities. Described here is the total synthesis of (4S, 10R)-4-hydroxy-10-nnethyl-11-oxododec-2-en-1,4-olide and a related butenolide containing anti stereochemistry at C10-C11. A three-module coupling strategy has been established for synthesis of the stereoisomers of the naturally Occurring butenolides by assembling the C3-C7 and C9-C12 fragments via double alkylation of a 1,3-dithiane. The C10-C11 stereochemistry could be easily controlled by an asymmetric aldol condensation, while the butenolide unit was efficiently constructed according to the ring-closing metathesis protocol. (C) 2008 Elsevier Ltd. All rights reserved.