alkyne Flashcards
NaNH2, R-MgX, LDA, NH2-
dbond given
anti elimnation and forms alkyne (tb)
strong base take away from anti sides
alc KOH/ heat
gmp of alkyne, nh2- added afterwards @geminal
double bond formation structure chosen where anti elimantion is possible
Pehle X(1) Alc KOH leke jayega and then X(2) ko strong base NH2-
triple bond in cyclic(benzenes)
yes/no
not possible
tri halo derivativeof CH3
The halo form- CH3-X
CH3-(C=O)-
Acetyl gives which test
CH3-I test forms yellow ppt
GMP of triple bond,, by terta halides
-(X2)C-C(X2). Reagent used?
2(Zn) is used to eliminate 4X to form 2(ZnX2)
How to form Higher alkyne
- take a tb
- add base (oh-/nh2-)
- Take out H2O to form carboanion R-C(tb)C(-)
- Add R’-X where R’ is 1’ or 2’
Which metal carbide forms ethyne?
CaC2 + H2O—> Ca(OH)2 + c(tb)c
Which metal carbide is used to from propyne?
Mg2C3 +H2O–> Mg(OH)2 + c-c(tb)c
By which method only ethyne can be prepaired?
From
Graphite(solid) +H2–silent electric discharge–> C2H2
Alkynes are odourless, except for?
Ethyne
Test of alkyne with Br2/H2O
reddish brown
Test of alkyne with alk. KMno4(baeyers solution)
Purple pink
Ammonical Silver Nitrate( Tollen reagent) gives Alkyne(@terminal) test
white ppt
Ammonical cuprous chloride gves alkyne test
( 2CuCl4+ 2 NH4OH)
Red ppt