A versatile synthetic approach to grandisol monoterpene pheromone

Abstract

A versatile and efficient synthetic procedure for the grandisol pheromone library has been established. The key feature of our synthesis involves a versatile and highly regioselective Pd(0)-catalyzed intramolecular allylic alkylation for the key cyclobutane skeleton of grandisol. In this connection, the concise synthesis of (±)-grandisol as well as mechanism study of Pd(0)-catalyzed regioselective cyclization as a key reaction have also been accomplished.

Recent advances in the total synthesis of cyclobutane-containing natural products

“…highly regioselective manner (Scheme 9). 30 The precursor 62 was prepared in 83% yield through a cross metathesis reaction between the known methyl hexanoate 59 and allyl carbonate 60 in the presence of the Grubbs II catalyst (61). Treatment of 62 with Pd(PPh 3 ) 4 in DMSO afforded the required cyclobutane 63 in 79% yield.…”

Organotransition Metal Chemistry of Terpenes: Syntheses, Structures, Reactivity and Molecular Rearrangements

“…Treatment with Pd(PPh 3 ) 4 in DMSO generated the allyl-palladium species, 79 , in which the sulphur-stabilised anion preferentially attacked intramolecularly in a 4-exo-trig fashion to form the desired cyclobutane ring, 80 . Further manipulation furnished grandisol [ 44 ]. The regioisomeric cyclohexene 81 was a minor side product.…”

Cyclobutane based “overbred intermediates” and their exploration in organic synthesis

“…Pd-Catalyzed Tsuji–Trost AA reaction was employed on a properly substituted acyclic substrate ( 22 ) to furnish the corresponding cyclobutane derivative with excellent diastereocontrol (25 : 1) as shown in Scheme 8. 12 It is interesting to note that a more stable cyclohexane derivative was not obtained in the reaction sequence, but the obtained cyclobutane derivative on exposure to the Pd catalyst furnished 23 (Scheme 8). The obtained cyclobutane derivative can be employed for the total synthesis of naturally occurring grandisol.…”