1816
with nz-chloroperbenzoic acid (1 equiv) in methylene chloride yielded the desired terminal epoxide’ selectively, and this gave upon reduction with excess diimide (N2H, H202)$the epoxy acetate VIII.’ The conversion of VI11 to the imino analog of the Cls Cecropia J H (IV)’ was accomplished by the method described above for the synthesis of I11 from V. The imino juvenile hormones I11 and IV alone and in combination with the C18 Cecropia J H were assayed on both the silkmoth pupa Antheraea polyphemus‘o and the bug Pyrrhocoris apterus.’’ In the former assay known amounts of hormone in 0.05 ml of olive oil were injected into the mesothoracic dorsum of a prolongedly chilled polyphemus pupa. For the latter assay a known amount of hormone in 1 pl of acetone was topically applied between the bases of the metathoracic legs of a starved freshly molted fifth instar larva which was then fed and allowed to go through metamorphosis. As seen in Table I, the imino esters I11 and IV ex-
+
Table I. Juvenile Hormone Activity of the Imino Juvenile Hormone Analogs 111 and IV on Chilled polyphemus Pupae
Compd
50 mg of olive oil CISJ H 0.01 pg
1 . 0 P8
IV 0 . 1 Pg 1.0pg 0.01 pg of CISJ H plus 111 or IV 0 . 1 pg of 111 1 . 0 pg of I11 0 . 1 pg of IV 1 . 0 fig of IV
No. assayed
Assay scoreb
3
0
6 3
2 5
0.003 0.03
3 6
0 0
0.03 0.4
3 3
0 0
0.03 0.3
5a
4
6a
5
5 3
2 3
0.03 0.3 0.03 0.3
pg/g live wt
16,000
a Includes only those initiating development within 1 day after injection. Reference 10.
hibited no intrinsic J H activity up to 0.4 pg/g live weight of polyphemus pupa. However, when injected in combination with a dose of CIS JH, they increased its activity. With 1 pg of the C16 imino compound the activity of the Cls J H was enhanced tenfold. This effect occurred only when the pupae began adult development immediately. The CIEimino hormone was not as effective but retained its synergistic activity for at least 2 days after injection. A similar potentiation of activity of the c18 J H was seen in the Pyrrhocoris assay. In this instance the Cl6 and cl8 imino JH’s had only slightly less intrinsic activity than the Cls J H I 2(i,e., about 15 pg/g live weight gave a type 111 larval-adult intermediate). But enhancement again was demonstrated by giving the Cle or (218 imino hormones along with 0.25 pg/g of C18 JH which alone did not interfere with metamorphosis. In such experiments about 2.5 pg/g of either imino (9) E. J. Corey and H. Yamamoto, J . Amer. Chem. Sot., 92, 6636 ( 1970).
(10) C. M. Williams, Biol. Bull., 121, 572 (1961). (11) C. M . Williams and I
