Synthesis of the Sex Pheromone of the Citrus Mealybug,Pseudococcus cryptus

Abstract

Scheme 1. Reagents: a) Pb(OAc) 4 , Benzene (75z, 3a:3b＝95:5); b) O 3 , MeOH, Then NaBH 4 , and Finally K 2 CO 3 (72z); c) HC(OMe) 3 , PPTS, THF; d) Ac 2 O, Then aq. NaOH (88z from 4); e) 6, DCC, DMAP, CH 2 Cl 2 (91z).Biosci. Biotechnol. Biochem., 67 (12), 2627-2631, 2003 Synthesis of the Sex Pheromone of the Citrus Mealybug, Pseudococcus cryptus The sex pheromone of the citrus mealybug (Pseudococcus cryptus ), [(1R,3R )-3-isopropenyl-2,2-dimethylcyclobutyl]methyl 3-methyl-3-butenoate, was synthesized from (＋)-a-pinene inˆve operational steps in a 43z overall yield. The synthetic pheromone was identical with the natural pheromone in 1 H-NMR and mass spectroscopic properties, and showed almost the same pheromonal activity as the natural pheromone.

The Absolute Configuration of the Sex Pheromone of the Citrophilous Mealybug, Pseudococcus calceolariae

“…The alcohol part of the pheromone compounds is a monoterpenol (or, as in the case of P. comstocki, a norterpenol), and it is related to maconelliol (compounds 1-3, Fig. 5; BierlLeonhardt et al, 1981;Arai et al, 2003;Nakahata et al, 2003;Zhang et al, 2004aZhang et al, , b, 2006Zhang and Amalin, 2005), lavandulol (compounds 4-8; Negishi et al, 1980;Hinkens et al, 2001;Zhang et al, 2004aZhang et al, , b, 2006Zhang and Amalin, 2005;Ho et al, 2007;Sugie et al, 2008), cyclopentylmethanol (compounds 10-12; Millar et al, 2005bMillar et al, , 2009Figadere et al, 2007), or chrysanthemol (9,13;Ho et al, 2009 and the present paper).…”

Sex pheromone of the pink hibiscus mealybug, Maconellicoccus hirsutus , contains an unusual cyclobutanoid monoterpene

“…Compound 8 was identified in 1998 as the sex pheromone of the oleander scale, Aspidiotus nerii (24). Compound 9 was identified in 1981 as the sex pheromone of the citrus mealybug, Planococcus citri (25), and similar structure 10 was identified as Pseudococcus cryptus sex pheromone in 2003 (26,27). Although the substituents are different, all of the above-mentioned semiochemicals contain an isopropenyl group on the ring.…”

Chemistry of the pheromones of mealybug and scale insects

“…Scheme 41 summarizes Nakahata's 5-step synthesis that utilized all ten carbon atoms of the starting material (+)-apinene 258. 100 Thus, treatment of (+)-a-pinene with Pb(OAc) 4 gave 267 with a small amount of allylic rearrangement product 268 (95 : 5 ratio). The order of addition and careful drying of the Pb(OAc) 4 were crucial for minimizing the formation of 268.…”