Invasive Stink Bugs and Related Species (Pentatomoidea)

Semiochemistry of Pentatomoidea 695

terminal double bond in 62 to the desired methyl ketone, (6R,10S)- 53. Analogously, sulfone (R)- 60 was
prepared from (S)-propylene oxide (Figure 15.11), and the remaining three diastereomers [i.e., (6S,10S)-
53, (6R,10R)-53, and (6S,10R)-53] were synthesized using the appropriate combinations of iodide 58 and
sulfone 60 chiral building blocks (Muraki et al. 2013).
A partial resolution of the mixture of all four stereoisomers of 6,10,13-trimethyltetradecan-2-one 53
was achieved on a β-DEX chiral stationary phase GC column limiting the possible configurations of
natural pallantione to the (6R,10S)- or (6S,10R)- isomers. Lastly, introducing an additional chiral cen-
ter into the molecule by reducing the ketone and acetylating the resulting alcohol, then analyzing the
acetates on the β-DEX column, allowed differentiation of the enantiomers. Based on these findings,
the absolute configuration of the male-produced compound was determined to be (6R,10S)-6,10,13-
trimethyltetradecan-2-one ((6R,10S)- 53 )(Fávaro et al. 2013).

15.2.14 Piezodorus guildinii (Westwood) and Piezodorus hybneri (Gmelin)
[Pentatomidae: Pentatominae: Piezodorini]

15.2.14.1 Sex Pheromone of Piezodorus guildinii

Piezodorus guildinii, commonly known as the redbanded stink bug, is a serious pest of soybeans in
South and Central America and, in the last decade, also the southern United States. Borges et al. (2007)
isolated and identified its male-produced sex pheromone from volatiles collected from male bugs. Live
male bugs or the synthetic pheromone attracted only females in Y-tube bioassays. Although males

O

HO O I

OTs

MeO 2 CMeO 2 C

CO 2 Me

a

e

I

O f

i j

O

O SO 2 Ph

SO 2 Ph

SO 2 Ph

OTs

g

h

b

55 56 57

(R)- 58 (S)- 58

(R)- 58

(S)- 60

61

62 (6R,10S)- 53

(R)- 60

(R)- 58 + (R)- 60

(S)- 58 + (S)- 60

(S)- 58 + (R)- 60

(6S,10S)- 53

(6R,10R)- 53

(6S,10R)- 53

59

cd

FIGURE 15.11 Syntheses of Pallantia macunaima sex pheromone (6R,10S)- 53 and its stereoisomers.
a)  1.  (CH 3 ) 2 CHCH 2 MgBr/Li 2 CuCl 4 , 2. TsCl/Et 3 N; b) NaCH(CO 2 Me) 2 ; c) LiCl/DMSO/H 2 O, 150-160°C; d) LiAlH 4 ;
e) I 2 /PPh 3 ; f) 1. CH 2 =CHCH 2 CH 2 MgBr/Li 2 CuCl 4 , 2. TsCl/Et 3 N; g) PhSO 2 Me/BuLi; h) BuLi/THF/DMI; i) Mg/MeOH;
j) O 2 /PdCl 2 /CuCl.