Controlling the Facial Selectivity of Asymmetric [4 + 2] Cyclo-additions: A Concise Synthesis of the cis-Decalin Core Structure of Superstolides A and B

Abstract

Regio, stereo and facial selective [4+2] cycloadditions between highly activated vinyl sulfones and 1,3-dienes derived from (R)-4-t-butyldimethyl-silyloxy-2-cyclohexen-1-one provide a powerful approach for the asymmetric synthesis of compounds containing the bicyclo[2.2.2]octanone carbon skeleton. This new methodology has been successfully applied to the asymmetric synthesis of the cis-decalin core structure of the potent anticancer marine natural products superstolides A and B.

Unexpected reactions of Grignard reagents with selected β-carboalkoxy substituted sulfinate esters

“…[1][2][3][4][5][6][7][8][9][10] The sulfone and sulfoxide containing adducts so formed can be adapted to create a variety of chemical building blocks [9][10][11][12][13][14] and bioactive compounds. [15][16][17][18] Sulfur acid derivatives have also been shown to activate dienophiles.…”

Design, Synthesis, and Biological Evaluation of Truncated Superstolide A

“…[4,5] So far the only completed total synthesis of superstolide A was accomplished by Roush and his coworkers. [5h] …”

“…[4] While working on the total synthesis, it became apparent to us that because of the structural complexity of the target molecules, it would be extremely challenging to develop a practical total synthesis that is capable of providing an adequate amount of material for biological investiga-tion, therapeutic evaluation and possible future clinical trials.…”

“…The cross-metathesis between olefin 19 [4a] and pinacol vinylboronate 20 proved to be quite challenging (Scheme 4). After much experimentation, it was discovered that employing the second generation of Grubbs-Hoveyda catalyst compound 19 was successfully converted to trans -vinylboronate 6 in 83% yield.…”

Development of novel anticancer agents based on natural products

“…88,89 The penultimate precursor of the borane polypropionate fragment 3.35 was synthesized by the similar synthetic methodology as reported by Jin. 80,91,94 The cross metathesis reaction between the vinylboronic acid pinacol ester 3.34 and the alkene 3.35…”