Stereocontrolled Total Synthesis of Hemibrevetoxin B
作者:Isao Kadota、Yoshinori Yamamoto
DOI:10.1021/jo9807619
日期:1998.9.1
The stereocontrolled total synthesis of hemibrevetoxin B (1) has been achieved in 56 steps and 0.75% overall yield from D-mannose. The intramolecular reaction of gamma-alkoxyallylstannane with. aldehyde is a key step for the present total synthesis. Thus, the BF3. OEt2-mediated reaction of 24 gave 6 as a sole product. We encountered difficulty in the synthesis of gamma-alkoxyallylstannane 30 from the corresponding allyl ether 29 in which the gamma-alkoxy substituent became sterically quite bulky. This problem was solved by developing the acetal cleavage method for the synthesis of gamma-alkoxyallylstannanes. The cyclization of 38 proceeded smoothly to give the key intermediate 5 in a highly stereoselective manner. Construction of the alpha-vinyl aldehyde and (Z)-diene moieties were performed using Nicolaou's protocol.
Total Synthesis of Hemibrevetoxin B
作者:I Kadota
DOI:10.1016/00404-0399(50)10972-
日期:1995.8.7
The total synthesis of Hemibrevetoxin B is described. A new cyclization approach, based on the Lewis acid mediated intramolecular cyclization of the gamma-oxo-substituted allylic tin having an aldehyde group, produced the 6-6-7-7 polycyclic ether skeleton of the natural product with high stereoselectivity. The H-1 and C-13-NMR spectra of synthetic hemibrevetoxin B was identical with those of natural product.
NICOLAOU, K. C.;VEALE, C. A.;HWANG, C. -K.;HUTCHINSON, J.;PRASAD, C. V. C+, ANGEW. CHEM., 103,(1991) N, C. 304-308
作者:NICOLAOU, K. C.、VEALE, C. A.、HWANG, C. -K.、HUTCHINSON, J.、PRASAD, C. V. C+
DOI:——
日期:——
Nicolaou, K. C.; Veale, C. A.; Hwang, C.-K., Angewandte Chemie, 1991, vol. 103, # 3, p. 304 - 308
作者:Nicolaou, K. C.、Veale, C. A.、Hwang, C.-K.、Hutchinson, J.、Prasad, C. V. C.、Ogilvie, W. W.