Enzymatic resolution of 1,1-dimethoxybut-3-en-2-ol and 1,1-dimethoxypent-4-en-2-ol, α-hydroxyaldehyde precursors for aldol-type reactions
摘要:
Hydroxyacetals 2 and 3 were resolved by acylation with vinyl acetate in the presence of lipases in organic media. The reverse reaction, the enzymatic hydrolysis of the corresponding acetates, was also highly stereoselective and provided the opposite enantiomers. (c) 2005 Elsevier Ltd. All rights reserved.
or by Prins cyclization of a trans-cinnamaldehyde with a chiral homoallylic alcohol. Goniothalamin was obtained as a cross-metathesis product of the diacetate and vinyl lactone. lactones - total synthesis - heterocycles - cyclizations - cryptofolione
A stereoselective and convergent formal approach to Salicylihalamide A and B is achieved through our recently developed strategy for the construction of polyketide precursors via Prins cyclisation. The approach mainly relies upon reductive opening of 1-iodomethyl cyclic ethers, Mitsunobu inversion and ring closing metathesis along with Prins cyclisation.
of epothilone A via organoboranes have been described. A modified procedure for the large-scale preparation of B-gamma,gamma-dimethylallyldiisopinocampheylborane from prenyl alcohol has been developed. This reagent, upon reaction with various aldehydes, provides the corresponding alpha,alpha-dimethylhomoallylic alcohols in high enantioselectivities. The application of this reagent for the synthesis of
This invention relates to compounds of general formula (I)
in which R
1
, R
2
, U, V, L, M, R
5
, m, X, Y and Z are as defined herein, and the pharmaceutically acceptable salts thereof, to pharmaceutical compositions comprising such compounds and salts, and to methods of using such compounds, salts and compositions for the treatment of abnormal cell growth, including cancer.
The Stereoselective Total Synthesis of Aculeatin A and B via Prins Cyclization
作者:J. Yadav、N. Thrimurtulu、M. Venkatesh、A. Prasad
DOI:10.1055/s-0029-1217144
日期:2010.2
The totalsynthesis of aculeatins A and B is described proving the versatility of Prinscyclization in natural product synthesis. The approach is convergent and highly stereoselective. Morpholine amide coupling with an alkyne and PIFA-mediated oxidative spirocyclization were utilized as key steps. aculeatins - Prinscyclization - morpholine amide - PIFA-mediated oxidative spirocyclization