The AB ring segment of gambierol (1) was synthesized from 2-deoxy-d-ribose in 23 steps. The key steps were Brown's asymmetric allylboration of the aldehyde 5 and the intramolecular hetero-Michael reaction of 7.
                                    由23个步骤由2-脱氧-d-
核糖合成甘比罗尔(1)的AB环片段。的关键步骤是布朗的醛的不对称allylboration 5和的分子内异迈克尔反应7。