Structure and Absolute Stereochemistry of the Anticancer Agent EBC-23 from the Australian Rainforest

Abstract

EBC-23 (2), a prostate anticancer agent, was isolated from the fruit of Cinnamomum laubatii (family Lauraceae) in the Australian tropical rainforest. Extensive NOE experiments enabled the relative stereochemistry of the proposed EBC-23 (2) structure to be determined. Total synthesis of both enantiopodes over nine linear steps, involving challenging RCM and spiroacetal cyclizations, confirmed the gross structure and relative and absolute stereochemistry.

New Casbanes and the First trans‐Cyclopropane seco‐Casbane from the Australian Rainforest Plant Croton insularis

“…[7] Considering the structural relationship between the cembranes, lathyranes, tiglianes andc asbanes, the fractionated extracts of Crotoni nsularis were subjected to further investigation by 1 HNMR guided screening. [9,10] Herein we report seven new cis- (9)(10)(11)(12)(13)(14)(15), and two new trans-cyclopropane casbanes…”

Metathetic Synthesis of Common and Medium-Sized Lactones: The State of the Art

“…The second compound is EBC 23 96, isolated from Cinnamon laubatii, which is an inhibitor of the growth of androgen-independent prostate tumor cells. The preparation of 96 involves a RCM step aided by microwave irradiation [167,168] (Scheme 35).…”

Supersilyl Protective Groups in Aldol Reactions

“…This spiroketal was isolated from the fruit of Cinnamomum laubatii, is active in vitro against several human cancer cell lines, and inhibited the growth of a human cancer xenograft in mice with no observable side effects [82,83]. The structure and absolute stereochemistry of EBC-23 was determined by Williams and coworkers in their 15-step total synthesis, 11 steps for the longest linear sequence.…”