9.When there is a choice in numbering though double bonds receive lower 三 numbers than do triple bonds 765432 HC-CCH, CH,CH,CH=CH 2 1-Hepten-6-yne 1-庚烯-6炔 CH hC-CCH, CHCH, CH,CH-CHCH 4-Methyl-7-nonen-1-yne 4-甲基7-壬烯-1-炔Organic Chemistry Organic Chemistry Xiamen Xiamen University University „ When there is a choice in numbering, though, double bonds receive lower numbers than do triple bonds. HC CCH 2CH 2CH 2CH CH 2 1-H epten-6-yne 1-庚烯-6 - 炔 7 6 5 4 3 2 1 H C CCH 2CHCH 2CH 2CH CHCH 3 CH 3 4-Methy l-7-n o nen - 1 - y n e 4-甲基-7-壬烯-1 - 炔