Total synthesis of brevetoxin B. 1. CDEFG framework

A new synthetic procedure uses a previously prepared intermediate to construct the CDEFG framework of brevetoxin B. Methods used for the design of oxocene and tetrahydropyran units help plan the synthetic strategy. The strategy involves various steps including Swern oxidation, hydrogenation, lactonizations and coupling steps. X-ray crystallography helps determine the structure of a lactone formed during the synthesis.