A novel and efficient route to the construction of the 4-oxa-tricyclo[4.3.1.0]decan-2-one scaffold

A short and efficient route to the synthesis of 4-oxa-tricyclo[4.3.1.0]decan-2-one scaffold 12 in good yield is reported. Essential to the synthesis was the implementation of selective protection of the catechol system in xanthone 2 with Ph2CCl2 and MOM groups. Subsequently, a biomimetic tandem Claisen/Diels–Alder reaction occurred to produce the desired tricyclic scaffold 11a as a single isomer. A rationalization of the excellent region and stereoselectivity of this transformation was also proposed.