![]() |
![]() |
|||||||
hypo
(Official Hive Approximator) 08-08-02 05:19 No 342972 |
![]() |
alkylation of 3-OH vs 4-OH benzaldehydes? | Bookmark | |||||
hi, if we look at the phenolates of 3-OH and 4-OH benzaldehydes, we see that in the 4-OH case, the phenolate is in resonance with the formyl group, whereas in the 3-OH case it isn't (if this is not clear, i can make a quick sketch of what i mean). 1) does that mean that in the 4-OH case the negative charge is more dislocated and thus the alkylation is _slower_ (maybe not noticeable) than in the 3-OH case? 2) does that mean that in the 4-OH case, the formyl group can also be alkylated? giving a strange compound (which i can't name)? 3) now suppose we have a MeO or other activating group in the 5 position. this would speed up the 4-OH alkylation (two negative charges on the ring), but would still leave the possibility of the formyl alkylation? i hope i ain't annoying people with my questions! ![]() couch terrorist |
||||||||
![]() |
![]() |
|||||||
![]() |
![]() |
|||||||
Rhodium (Chief Bee) 08-08-02 08:15 No 343011 |
![]() |
As far as I know, aldehyde allylation require a ... | Bookmark | |||||
As far as I know, aldehyde allylation require a catalyst like Sm/In/Mg etc... |
||||||||
![]() |
![]() |
|||||||
![]() |
![]() |
|||||||
GC_MS (Hive Bee) 08-08-02 08:59 No 343031 |
![]() |
Alkylation of the formyl | Bookmark | |||||
Alkenylation of the formyl is done a la Perkin. anisaldehyde + EtCOONa -> H2O + MeO-C6H4-CH=CMeCOONa MeO-C6H4-CH=CMeCOOH - CO2 = anethole Old trick from the perfume industry ![]() SWiM doesn't have the necessary articles handy to help you much further hypo. Till now, he mainly need DEmethylation reviews ![]() Doped(TM) since 19.... euhm... a long time ![]() |
||||||||
![]() |
![]() |
|||||||
![]() |
![]() |
|||||||
hypo (Official Hive Approximator) 08-08-02 09:23 No 343040 |
![]() |
heh... | Bookmark | |||||
thanks. rhodium: i see how normal aldehydes are pretty unreactive, but shouldn't benzaldehyde and especially benzaldehydes with an -O- in 4 position be pretty reactive? GC_MS: alk(en)ylation on the formyl group is _not_ what i want. rather my concern was if, when alkylating a 4-formyl-phenolate, etherification of the formyl group would be a side reaction. if not, then why not? this is the compound i'm talking about in the case of alkylation with propyliodide: Molecule: watchamacallit ("O=C1C=CC(=COCCC)C=C1") couch terrorist |
||||||||
![]() |
![]() |
|||||||