A Global and Local Desymmetrization Approach to the Synthesis of Steroidal Alkaloids: Stereocontrolled Total Synthesis of Paspaline
作者:Robert J. Sharpe、Jeffrey S. Johnson
DOI:10.1021/jacs.5b02631
日期:2015.4.22
A stereocontrolled totalsynthesis of the indole diterpenoid natural product paspaline is described. Key steps include a highly diastereoselective enzymatic desymmetrization, substrate-directed epoxidation, Ireland-Claisen rearrangement, and diastereotopic group selective C-H acetoxylation to assemble the target with excellent stereofidelity. The route and results described herein outline complementary
A multistep rearrangement from 2,2-disubstituted-1,3-cyclohexanediones to 3-substituted 2-cyclohexenones via phosphonate anions and its application to a formal synthesis of (.+-.)-.alpha.-acoradiene
作者:Yoshinori Yamamoto、Toshiaki Furuta
DOI:10.1021/jo00300a003
日期:1990.6
A Scalable Protocol for the Regioselective Alkylation of 2-Methylcyclohexane-1,3-dione with Unactivated sp3 Electrophiles
A method for the C-selective alkylation of 2-methylcyclohexane-1,3-dione with unactivated sp(3) electrophiles is accomplished via alkylation and subsequent deprotection of the derived ketodimethyl hydrazones. The present method provides a high-yielding entry to dialkyl cycloalkanones that cannot be accessed via direct alkylation of 2-methylcyclohexane-1,3-dione. The title reaction may be useful in the scalable preparation of terpene and steroidal building blocks in the arena of natural product synthesis.
YAMAMOTO, YOSHINORI;FURUTA, TOSHIAKI, J. ORG. CHEM., 55,(1990) N3, C. 3971-3972