The viability of the key steps in our approach to the novel sesquiterpene breynolide (1) has been verified by preparation of the hydrobenzothiophene 16. The sequence features a Diels-Alder reaction of 10 with 7 to lead eventually to 13; subsequent dipolar cycloaddition of 13 with a functionalized nitrile oxide gave 16.
The viability of the key steps in our approach to the novel sesquiterpene breynolide (1) has been verified by preparation of the hydrobenzothiophene 16. The sequence features a Diels-Alder reaction of 10 with 7 to lead eventually to 13; subsequent dipolar cycloaddition of 13 with a functionalized nitrile oxide gave 16.